1. Field of the Invention
The present invention relates to wireless voice systems, and, in particular, to tunneling wireless voice data over various networks using software-defined vocoders.
2. Description of the Related Art
With the Internet and the associated Internet Protocol (IP) gaining popularity with customers, it is now possible to use IP via the Internet (or an intranet) to deliver wireless voice services, also known as Voice-over-IP (VoIP). Next generation cellular networks, public land mobile networks (PLMNs) and public switched telephone networks (PSTNs) most likely will be implemented using IP networks. In IP networks, it is critical to best utilize system resources and reduce delays.
One of the key challenges for wireless systems using VoIP is the issue of delay. The encoding and decoding of voice into digital data (also known as “vocoding”) can introduce substantial delay into VoIP. The introduction of vocoding delays has been a major hindrance to the deployment of VoIP.
Moreover, significant cost savings can be realized by the elimination of specialized vocoder hardware. For example, a typical single-mode handset requires a vocoder that costs approximately $5 (and provides about 20 MIPs of processing power), while a typical dual-mode handset requires two vocoders. The cost of a vocoder is roughly the same cost as a processor for a handset (which only needs about 5 MIPS of processing power). One way to reduce costs is to eliminate hardware-based vocoders, and have the processor perform some of the functions of the vocoder. Moreover, this allows handsets to be smaller and less complex.